#include <iostream>
#include <vector>
using namespace std;
struct node
{
    int x, y;
    bool operator==(node temp)
    {
        return this->x == temp.x && this->y == temp.y;
    }
};

int main()
{
    node B, h;
    cin >> B.x >> B.y >> h.x >> h.y;
    int horse_loc[8][2] = {
        h1 + 2,
        h2 + 1,
        h1 + 1,
        h2 + 2,
        h1 - 1, h2 + 2, h1 - 2, h2 + 1, h1 - 2, h2 - 1, h1 - 1, h2 - 2, h1 + 1, h2 - 2, h1 + 2, h2 - 1};
}